Tibia fracture after fibula resection for distal peroneal bypass.

The lateral approach to the distal peroneal artery has been used by vascular surgeons for 25 years. No complications specifically related to this approach have previously been reported. We reviewed 18 cases of peroneal bypass for limb salvage using the lateral approach with fibula resection and found that two of these cases had ipsilateral tibia fractures within 1 year of the bypass. Eight out of 18 cases were women, and two of these eight had tibia fracture. Both women suffered from osteoporosis. We conclude that tibia fracture is a possible complication of this approach, especially in elderly women with osteoporosis.

Clostridial mycotic aneurysm of the thoracoabdominal aorta--a case report.

Clostridial infection of the aorta is a rare and life-threatening condition. The management of a mycotic aneurysm involving the thoracoabdominal aorta due to Clostridium septicum infection is presented. Successful surgical management of the aortic infection involved arterial resection, wide debridement of the surrounding tissues, and in situ graft replacement. Sixteen additional cases of clostridial infection of the aortoiliac segment reported in the literature are also summarized. In ten of these 17 cases, an associated colonic adenocarcinoma was documented.

Mycotic aneurysm and aortic graft infection presenting with vertebral body destruction requiring debridement and stabilization--a report of two cases.

Vertebral osteomyelitis may occur with mycotic aneurysms or infected aortic grafts. A high index of suspicion for these concurrent processes as well as appropriate preoperative evaluation and interspecialty communication is critical for appropriate diagnosis and treatment. Extraanatomic bypass, wide debridement of necrotic soft tissue and bony structures, and concurrent bony stabilization are important aspects of treatment.

Long-term follow-up of reoperative carotid surgery.

BACKGROUND: We examined our long-term results of carotid reoperation to identify risk factors for morbidity and secondary recurrence. METHODS: Medical record review revealed 27 patients had reoperative surgery for recurrent stenosis. Demographics, operative details, pathology, clinical outcome, and follow-up imaging results were reviewed. RESULTS: No neurologic deficits and no mortalities were noted perioperatively. Long-term follow-up (average 54 months) revealed an 85% 5-year and 29% 10-year estimated survival. The 5- and 10-year estimated neurologic event rates were 15% and 35%, respectively. These included 3 ipsilateral strokes and 1 ipsilateral TIA; only the TIA involved secondary restenosis. Follow-up imaging revealed a 21% incidence of secondary restenosis, occurring more frequently in patients with hyperlipidemia (P < 0.05) and previous contralateral endarterectomy (P < 0.05). CONCLUSIONS: (1) Reoperation provides long-term protection from stroke due to recurrent stenosis. (2) Secondary restenosis rates appear higher than those for primary surgery. (3) Hyperlipidemia and contralateral endarterectomy are risk factors for secondary restenosis.

Early carotid endarterectomy in selected stroke patients.

Although there are several reports suggesting the safety of performing carotid endarterectomy (CE) within 4 weeks (early) of a nondisabling stroke, at many institutions it is not standard practice. Benefits of early surgery may include reduction in the number of strokes or carotid occlusions during the time between stroke and surgery, as well as a reduction in the cost of medical care due to the elimination of interval anticoagulation and close follow-up. This review examines the outcomes of early CE in selected patients after a nondisabling stroke. A total of 1065 CEs were performed between November 1991 and April 1998. Seventy-five patients were identified by computerized hospital record and office chart review as having CE after a nondisabling stroke. Criteria for early surgery included 1) nondisabling stroke ipsilateral to a carotid stenosis >50%, 2) neurological stability, and 3) no evidence of hemorrhagic stroke or significant cerebral edema by CT/MRI evaluation. This review suggests that early CE can be performed in selected patients with an acceptable perioperative morbidity and mortality.

Comparison of Doppler US and CT angiography for evaluation of renal artery stenosis.

RATIONALE AND OBJECTIVES: The authors compared Doppler ultrasound (US) with computed tomographic (CT) angiography in the evaluation of stenosis of the main renal artery. MATERIALS AND METHODS: Fifty-six patients who had undergone conventional angiography of the renal arteries participated in a prospective comparison of Doppler US (45 patients) and CT angiography (52 patients). US evaluation included both the main renal artery and segmental renal arteries. RESULTS: There were 27 main renal arteries with at least 50% stenosis in 20 patients. In 36 patients, there was no significant stenosis. All cases of main renal artery stenosis detected with Doppler US of the segmental arteries were also identified with Doppler US of the main renal artery. The by-artery sensitivity (63%) of US of the main renal artery was greater than that (33%) of US of the segmental arteries. CT angiography was more sensitive (96%) than Doppler US (63%) in the detection of stenosis, but the specificity of CT (88%) was similar to that of US (89%). The difference in the area under the receiver operating characteristic curve (AUC) between CT (AUC = 0.94) and US (AUC = 0.82) was statistically significant (P = .038). CONCLUSION: Doppler US of the main renal artery is more sensitive than Doppler US of segmental arteries in the detection of stenosis. CT angiography is more accurate than Doppler US in the evaluation of renal artery stenosis.

Role of thrombin in endothelial cell monolayer repair in vitro.

PURPOSE: We examined the effect of thrombin on human iliac artery endothelial cell monolayer repair and proliferation after denuding vascular injury. METHODS: Human iliac artery endothelial cell monolayer repair was determined by scrape wounding confluent monolayers and measuring the advancement of the cells into the wounded area for 3 days. Proliferation studies involved plating human iliac artery endothelial cells at one tenth confluence and counting the increase in cell number every 2 days for a 2-week period. Proliferation during monolayer repair was examined by determining bromodeoxyuridine uptake in cells located at the leading edge of a scrape-wounded monolayer. RESULTS: Thrombin (1 to 8 U/ml) inhibited human iliac artery endothelial cell monolayer repair in a concentration-related, reversible manner. The effect was augmented by decreasing serum concentration and was independent of the presence of endothelial cell growth supplement. Inactivation of thrombin's proteolytic site with diisopropylfluorophosphate eliminated its effect on monolayer repair. Thrombin (0.5 to 8 U/ml) inhibited human iliac artery endothelial cell proliferation in a dose-related manner. This effect was augmented by decreasing serum concentration. Finally, thrombin (4 U/ml) inhibited the proliferative response of cells located at the leading edge of wounded monolayers compared with control groups. CONCLUSION: Thrombin inhibits human arterial endothelial cell monolayer repair and proliferation after denuding vascular injury.

Role of selective arteriography in the diagnosis of a ruptured middle colic artery aneurysm.

A case of a ruptured middle colic artery is reported. The diagnosis was initially overlooked and eventually made by selective arteriography. Aneurysms of visceral arteries are rare and rupture of them even more infrequent. Awareness of this potentially fatal and treatable entity should enable early detection by selective visceral arteriography. The roles of embolization and surgery in the management of visceral aneurysms are discussed.

Treatment of iatrogenic femoral artery injuries with ultrasound-guided compression.

Iatrogenic injuries of the groin are becoming more common after increasingly sophisticated vascular intervention. These injuries are accurately detected by duplex and color Doppler ultrasonography. Recent treatment of these lesions by ultrasound-guided compression repair (UGCR) has been described. During a 1-year period we identified 18 femoral artery injuries, including 17 pseudoaneurysms and one arteriovenous fistula. Three of the pseudoaneurysms thrombosed spontaneously before attempted treatment. The remaining 15 lesions underwent a trial of UGCR. Successful closure was accomplished in 10 patients (56%). Seven of these lesions were successfully treated during the initial session, and thrombosis was accomplished after repeat compression in three additional lesions. Three patients who were given anticoagulants had a failed UGCR, but their pseudoaneurysms thrombosed after administration of anticoagulants was discontinued. Two patients had failed UGCR and required operation. Seven (88%) of eight patients who were not given anticoagulants were successfully treated. In contrast only two (29%) of seven patients given therapeutic doses of anticoagulant medication were successfully treated by the technique. There was no statistical difference between mean pseudoaneurysm diameter, mean width and length of pseudoaneurysm neck, or depth of pseudoaneurysm neck from skin surface in patients in whom successful initial closure was achieved when compared with those patients in whom the initial attempt failed. UGCR is a safe, simple, noninvasive technique that can be used to treat many femoral artery injuries that traditionally were treated with surgery. The technique can be applied by any laboratory that has the necessary ultrasonography equipment and is currently the method of choice for treating uncomplicated iatrogenic femoral artery injuries at our institution.

Cultured and immediately procured endothelial cells: current and future clinical applications.

Great progress has been made in the last several years in our ability to culture human endothelial cells. In addition, techniques to immediately procure and utilize these cells have also been developed. The purpose of this paper is to present an overview of the current and potential uses of these cells in both vascular and nonvascular conditions. It is likely that endothelial cells will be used in a variety of applications in the near future. Immediately procured and cultured cells will be used to resurface vascular prosthetic grafts. They may also be used on the surface of vessels following procedures such as balloon angioplasty or atherectomy. In addition, they may be placed upon the surface of implantable devices such as expandable stents. Through the mechanism of genetic engineering, these cells may be modified to produce proteins, which may modify thrombogenicity and perhaps decrease the rate of recurrent stenosis by influencing cellular hyperplasia. Genetically modified endothelial cells also have great potential in nonvascular disease. Their contact with circulating blood makes them an ideal cell for production of proteins to correct systemic conditions such as the insulin deficiency found in diabetes mellitus. The application of endothelial cell biology in both vascular and nonvascular science represents one of the most exciting fields of research active today.

Origin of cells that line damaged native blood vessels following endothelial cell transplantation.

Endothelial cell (EC) transplantation has been proposed as a method to reduce the thrombogenicity of both vascular grafts as well as injured native blood vessels. While techniques have been developed to establish EC monolayers on these surfaces, a major question that remains is whether the cells that exist on the blood flow surface are the same cells placed on the surface at the time of transplantation. We have developed an intravital fluorescent staining technique that permits isolated, autologous, fat-derived microvascular endothelial cells (MVEC) to be labeled and subsequently detected following their transplantation. In our study, rat abdominal aortas (AA) were injured with a 3F embolectomy catheter, and the injured surfaces were immediately treated with fluorescently labeled MVEC. Five days after transplantation, AA were evaluated by both scanning electron and fluorescence microscopy. Results of scanning electron microscopy showed the existence of nonthrombogenic regions in the areas of injury, and fluorescence microscopy of the identical areas established that these cells contained fluorescent dye. Our results indicate that the cells that line these injured areas of native vessels are the same cells that were originally transplanted. Our intravital fluorescence technique provides a method to trace the origin and disposition of transplanted cells on the vascular surfaces.

Efficacy of thrombolysis in infrainguinal bypass grafts.

The initial outcome of a consecutive series of 43 intra-arterial urokinase infusions for thrombosed infrainguinal grafts in 37 patients was analyzed. There was an 88% (38/43) technical success rate (complete clot lysis) and a 74% (32/43) clinical success rate. Complications occurred in 10 patients (23%) and were related to bleeding in four patients (9%). Patient age, graft age, location, material, and the duration of occlusion did not significantly influence the initial outcome, although there was a trend toward a higher bleeding complication rate among grafts less than or equal to 1 month of age at the time of thrombolysis. A second group of 43 infrainguinal grafts successfully recanalized using regional infusions of thrombolytic agents were followed for long-term patency. This group included 32 grafts successfully treated with urokinase and 11 grafts recanalized with streptokinase. By life-table analysis there was a 55.6% 1-year patency, which fell to 42.4% at 4 years. Vein grafts had significantly (p = 0.01) better long-term patency than prosthetic grafts (69.3% versus 28.6% at 30 months). Grafts with flow-limiting lesions identified and corrected by angioplasty or surgery also had significantly (p = 0.01) better long-term patency than those without such lesions (79.0% versus 9.8% at 2 years). Based on the results of our study compared with a survey of long-term results following secondary surgical procedures for thrombosed infrainguinal grafts, thrombolysis can be recommended in several circumstances. Thrombolysis is indicated for thrombosed vein grafts or when thrombus is present in distal runoff vessels. Thrombosed prosthetic grafts should be replaced by autogenous vein grafts whenever possible.(ABSTRACT TRUNCATED AT 250 WORDS)

Thrombus-free, human endothelial surface in the midregion of a Dacron vascular graft in the splanchnic venous circuit--observations after nine months of implantation.

The addition of an endothelial cell lining to a prosthetic vascular graft may reduce the thrombogenicity of the blood-contacting surface. An endothelialized mesoatrial graft was implanted in a patient with Budd-Chiari syndrome caused by a primary inferior vena caval leiomyosarcoma. During the initial surgery a Dacron vascular graft was preclotted with plasma and then lined with microvascular endothelial cells derived from the patient's subcutaneous adipose tissue. The patient did well initially but 9 months later required resection of a mechanical stricture of the graft that occurred as it passed beneath the costochondral junction. Grossly, the luminal surface of the resected graft was free of thrombus, with a smooth, glistening, white surface. Light microscopy demonstrated a surface layer of cells morphologically consistent with an endothelial cell monolayer, a subendothelial layer composed of extracellular matrix and spindle-shaped cells, and granulation tissue around the Dacron fabric. Immunohistochemistry and electron microscopy confirmed the presence of vascular endothelium on the luminal surface. This report documents the successful achievement of a human endothelial cell monolayer that persisted for 9 months in the midportion of a Dacron vascular graft.

Insertion and recovery of a new retrievable vena caval filter. Work in progress.

A new retrievable inferior vena cava (IVC) filter was tested in nine pigs. Insertion was through a 14 French sheath using both the femoral and jugular approaches. All insertions were successful, and there was a 100% postinsertion IVC patency rate (8/8 pigs at one week and 1/1 pig at one month). Addition of an apical hook to the filter design allowed transjugular retrieval of two filters at one week postinsertion. Three of nine filters migrated to the upper IVC. The filter's design allows paraxial blood flow despite trapped thrombus and inhibits filter tilting. In vitro, the filter captured 95% to 100% of 5 X 5 mm clots. If problems with migration can be solved, the new filter may provide effective short- and long-term prophylaxis against pulmonary embolism.

Kinetics of endothelial cell-surface attachment forces.

Physical and biochemical forces exist that are necessary for the persistent attachment and function of ECs on native and prosthetic blood vessels. The optimization of conditions that permit regeneration of these attachment forces may allow rapid establishment of a durable, biocompatible EC monolayer. We examined the effects of three major factors, protein substrate, EC incubation time, and shear stress, on the attachment kinetics of human adult ECs to two different polymers. ECs were incubated up to 30 minutes on polymers (PS or PET) coated with extracellular matrix proteins: collagen I/III, fibronectin, collagen IV/V, laminin, gelatin, or saline control. After incubation, continued attachment in the presence of shear stress (created in a rotating disc device) between zero and 90 dynes/cm2 for 30 minutes was evaluated. Maximal adherence was observed on all substrates by 30 minutes. Therefore, after a 30-minute incubation, the percentage of cells attached (postshear ECs/preshear ECs/preshear ECs X 100) was measured as a function of shear stress. ECs attached to a matrix of fibronectin or collagen I/III demonstrated shear-resistant adherence after as little as 5 minutes of static incubation before initial shear exposure. By 30 minutes, more than 90% of the ECs on both matrices demonstrated the ability to remain attached in the presence of 90 dynes/cm2 of shear stress. We conclude that forces that attach ECs to surfaces are affected by temporal factors (incubation time) and substrate composition and may be quantified with a defined shear stress detachment assay. Understanding and manipulating these temporal physiochemical parameters should allow one to re-create an optimal EC monolayer on a blood-contacting surface.

Use of the isolated perfused kidney model to assess the acute pharmacologic effects of cyclosporine and its vehicle, cremophor EL.

"Nephrotoxicity" secondary to cyclosporine and its clinically used vehicle, Cremophor EL, was examined in the isolated perfused rat kidney model. This model allows the serial determination of renal hemodynamic and tubular functional studies over a 3-hr duration using a normothermic, low hematocrit (13-15%) perfusion system. Initial studies indicated that the addition of small quantities of Cremophor EL resulted in marked renal vasoconstriction with decreased renal blood flow and deterioration in renal tubular function. These effects were highly significant and were of the same magnitude whether or not cyclosporine was present in the system. Cyclosporine was therefore examined after being dissolved in another vehicle, methanol. A 10% (v/v) amount of plasma was necessary in the perfusate to prevent significant adsorption of cyclosporine to the perfusion apparatus. Cyclosporine at concentrations below 100 ng/ml resulted in minor changes in renal hemodynamics. Beginning at 100 ng/ml glomerular filtration rate dropped significantly and renal vascular resistance increased three-fold. Fractional excretion of sodium significantly increased and the urine:plasma inulin ratio significantly decreased. We conclude that the clinically used drug vehicle, Cremophor EL, has significantly adverse effects on renal hemodynamics and tubular function. In addition, CsA causes similar renal toxicity in a dose-dependent fashion. Simultaneous administration of these two nephrotoxic agents could contribute to the high incidence of acute renal failure seen after transplantation. These observations suggest that an alternate vehicle with less renal toxicity might significantly decrease the incidence of this clinical problem.

Complications encountered with the use of the Greenfield filter.

The Greenfield filter can be used with a low complication rate provided one adheres to certain principles. First, preoperative venography to define the inferior vena caval anatomy will help avoid difficulties associated with anatomic variations. At the time the study is carried out, it would be extremely useful if the radiologist places a radiopaque marker at the level of the renal veins. This will ensure that filters will be placed in the infrarenal position when appropriate, thus preventing occasional inadvertent discharge, particularly into the right renal vein. Second, use of a guide wire greatly facilitates passage of the introducer and accurate intracaval positioning. Third, intraoperative technical errors must be recognized and promptly corrected. Finally, meticulous postoperative follow-up is essential, and recurrent embolism or any change in filter position requires repeat roentgenography of the vena cava to guide appropriate corrective treatment.

Renal autotransplantation and extracorporeal reconstruction for complicated benign and malignant diseases of the urinary tract.

Renal autotransplantation was performed in five patients and extracorporeal vascular reconstruction was required in two of these cases. One had a carcinoma of the mid-ureter with a solitary kidney. Two patients had ureteral injury. One was iatrogenic from a prior operation, and the other had intrinsic ureteral disease secondary to schistosomiasis. The fourth patient had renovascular hypertension with disease extension into the interlobar renal arteries and a single kidney. The final patient had a large, renal arteriovenous malformation and polycystic kidneys. All have functioning grafts at follow-up ranging from 10 to 36 months. There is no evidence of tumor recurrence after 30 months in the patient with ureteral malignancy. The patient with renovascular hypertension has adequate blood pressure control with medication 12 months after surgery. His creatinine which had risen in the post-operative period to 4.2 mg/dl, has returned to its pre-operative valve of 1.8 mg/dl. None of the other four patients had any post-operative decline in renal function. These cases illustrate that the technique of nephrectomy, extracorporeal surgery, and renal autotransplantation can be applied to a variety of benign and malignant diseases of the kidney and ureter not amenable to conventional in-situ correction, thus allowing maximal preservation of renal parenchyma. We also have demonstrated that the procedure can be successfully performed in the presence of significant infectious risk (Case 2: indwelling nephrostomy), and retroperitoneal infection (Case 3: schistosomiasis). We feel that this procedure is currently underutilized.(ABSTRACT TRUNCATED AT 250 WORDS)